大型放射光施設 SPring-8

問い合わせ番号

INS-0000000308

Imaging Plate system for the X-ray diffraction study under high pressure conditions

  The Imaging Plate system was designed to study the structure and physical properties of materials under high pressure conditions.
  Fig. 1 shows a schematic view of the Imaging Plate system installed at BL04B2. This system consists of 4D slit, X-ray shutter, ionization chamber, collimator, goniometer and imaging plate detector (detector area is 300 mm × 300 mm, Rigaku R-AXIS IV++). A camera length (distance from the sample position to the detector) can be changed from 270 mm to 1470 mm. A diamond anvil cell (DAC) is mounted on this diffractometer. A sample is enclosed in a DAC, which can generate high pressure, and the diffraction from the sample is detected by the imaging plate detector.
  The imaging plate detector is also used as a detector for small angle X-ray scattering for supercritical fluids in the high pressure vessel.

• Table 1. The specifications of DAC

  Temperature	Room temperature High temperature (up to 1000 K using the electric heating)
  Pressure	up to 200 GPa
  Beam size	more than 0.04 mm × 0.04 mm

  
  

  Fig. 1. A schematic view of the imaging plate system installed at BL04B2

  
  Fig. 2. X-ray diffraction patterns of CeSb at 4.2 GPa (1) and at 24 GPa (2)
  (1) a = 6.26 Å, Fm3m, NaCl-type structure
  (2) a=3.73 Å, c=3.11 Å, P4/mmm, Tetragonal-type structure
  

  Fig. 3. Faber-Ziman total structure factors, S(Q), for SnI₄ at 35, 45 and 55 GPa on compression and at 25 GPa on decompression

    The use of high energy x-ray of 61.7 keV makes it possible to cover a wide range of the wave number, Q (= 4πsinθ/λ), up to ∼ 16 Å^-1 even on high-pressure experiments using diamond anvil cell (DAC), which restricts the maximum value of Bragg angle.

References

1. Y. Ohishi, M. Isshiki, N. Ishimatsu and N. Hamaya: SPring-8 user report #1999B0148-ND-np.
2. A. Ohmura, N. Hamaya, K. Sato, C. Ogawa, M. Isshiki and Y. Ohishi: J. Phys.: Condens. Matter, 14 (2002) 10553.